When a child is harmed, adults react quickly. When a reporter writes about an 8-year-old boy who is being injected with heroin, a thousand voices ask, "What can be done to help this child? Who is he? What is the mother's name?"

If the reporter and the newspaper are pledged to secrecy, they are not merely criticized, they are reviled. They are charged with immoral or amoral conduct, and with callousness. They are scorned for disregarding the child's welfare, and for what is perceived to be their selfish preoccupation with their First Amendment rights.

"This saddens me because it shows a lack of understanding of one of the basic rights of a free people. When the First Amendment ordered Congress to make no law abridging the freedom of speech, or of the press, it did so to guarantee everybody's rights, not merely the rights of the press.

What is at stake is not only Janet Cooke's right to report the truth but your right to hear her, and your right thereafter to form whatever opinion you wish and to make whatever comment you wish. Unless everybody has a right to speak, nobody's right to hear is secure.

One way to describe a journalist's function is to say that he holds up a mirror, so that the community can see itself.

His mirror must be honest. It must show man's vices as well as his virtues, his failures as well as his successes. It reflects the nation's riches and industrial might, but also its poverty and misery. It shows us in our moments of togetherness and it shows the prejudices that tear us apart.

I am not of the opinion that the Constitution gives me special privileges. But I know I am fortunate to be following my profession in a free country in which every citizen, even a journalist, is free to speak and write as he pleases. Life must be hell for journalists who are forced to take orders from a government that hands them an amusement park mirror that distorts distorts reality and says, "Here. Hold up this mirror for the people to look into."

Staff writers Thomas Morgan and Ron Shaffer told us on Sunday that "inadequately staffed and poorly funded city agencies are doing little to help hundreds of Washington children" who are drug addicts.

These children are not unlike the 8-year-old "Jimmy" about whom Janet Cooke wrote. Many are from 8 to 12 years of age, and are still in elementary school.

Janet was permitted to hear and see what was going on only because she gave her word beforehand that she would not reveal the identities of the people involved. Given that proposition, what would you have done?

Should Janet have refused to promise that she would not reveal names, thereby losing her chance to alert the community to the problem? Should she have given her word and kept it, even at the risk of going to jail? Or should she have given her word, gotten the story, and then betrayed the people who enabled her to publish the truth about a vicious condition that threatens all our children, not just one?

I happen to think my colleague and my newspaper did what their profession requires of them. They held up an honest mirror.

Fortunately, the community was shocked by what it saw. I hope it was shocked again by Sunday's front page revelation that many users and dealers are now teen-agers and preteens.

Now, perhaps, an aroused public opinion will generate programs that will help Jimmy and hundreds of others like him.

For example, Morgan and Shaffer wrote that school authorities are well aware of drug-related problems but have enunciated no clear policy on how to handle them. Nor is there a training program to help either teachers or parents cope with them.

A policeman who has specialized in drug problems tells me that every police jurisdiction in our area has skilled personnel available who could help parents and teachers recognize and deal with children who have drug problems. "Much can be done," he told me, "and we're ready to help do it. But nobody ever asks us."